Soldering device

ABSTRACT

A soldering tool and method which utilizes controlled capillary attraction of the solder and the tool to regulate solder flow into and out of the tool tip and on and off the workpieces.

United State'sPatent 1 3,575,336

[72] Inventor Franklin W. Booth 1,626,552 4/1927 Quillen 228/52 Hampton,Va. 2,462,131 2/1949 Rustin 228/53 [21] Appl. No. 777,764 2,491,16512/1949 De Rugeris 228/53 [22] Filed Nov. 21,1968 3,443,734 5/1969Fortune 228/52 [45] Patented Apr. 20, 1971 3,484,033 12/1969 Sachs228/51 [73] Assignee the United States of America as represented FOREIGNPATENTS by Namna' 533,005 2/1941 Great Britain 228/52 Aeronautics andSpace Administration.

Primary Examiner-John F. Campbell Assistant Examiner-Ronald J. ShoreSOLDERING DEVICE Attorneys- Howard J. Osborn, John R. Benefiel and G. T.

3 Claims, 5 Drawing Figs. McCoy [52] U.S. Cl 228/53, 219/229 [51] Int.Cl B23k 3/04 [50] Field ofSearch 228/51, 52,

ABSTRACT: A solderin tool and method which utilizes [56] ReferencesCited controlled capillary attra tion of the solder and the tool toUNITED STATES PATENTS regulate solder flow into and out of the tool tipand on and off 1,457,508 6/1923 Dellman 228/53 theworkpieces.

Patented April 20, 1971 3 3,575,336

FIG. 2 3 FIG. 3 FIG. 4

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INVENTOR. FRANKLIN w. BOOTH ATTORNEYS I in order to attain a reasonableworking speed and to avoid excess solder deposits on the joints, andalso to maintain uniform solder deposits. Other devices have also beendeveloped to remove excess solder from joints or to remove isolder whendisconnecting soldered joints. These prior art 1 devices usually reliedon various suction arrangements, or

solder reservoirs with a valve control. In general, these devices sufferfrom the drawbacks of relative complexity and the lack of sufficientlyprecise control over solder flow necessary for uniformly tinnedconnections.

Therefore, it is an object of the present invention to provide a simplesoldering device which can yield uniformly proper solder deposits onsoldered connections.

It is a further object to provide a method of soldering a connection soas to produce uniformly perfect joints.

It is another object to provide a simple device for preciselycontrolling solder flow on and ofi' a connection.

Basically, these objects are accomplished by providing controlledcapillary attraction of the solder and the soldering device by use of asolder wettable passage in the device.

FIG. I shows in partial section a soldering device according to thepresent invention.

FIG. 2 shows an enlarged view of a partial section of the tip of thedevice shown in FIG. 1.

FIG. 3 shows an enlarged partial section of a tip charged I with solderand with the control wire inactive.

FIG. 4 shows an enlarged partial section of a tip with the control wireactivated.

FIG. 5 shows a partial section analternate form of the invention. I

Referring to FIG. I, lo'indicates a soldering device suitable forconnecting wires, etc., in general electronic work. This device maybe ofconventional construction in most regards, having a handle I2, insulator14', radiation shield 16, heating element 18 supplied with electricpower through lines 20, and a working tip 22.

This device is nonconventional in that a solder control arrangement 24has been added. This arrangement is composed of a control lever 26,which may be rotatably connected to toolby means of a bracket 28.Secured to an through a bracket 34 and into a passage 36 bored in thetip 22. A spring 38 biases the assembly so as to cause the control wireto advance into thepassage 36 whenthe lever 26 is released.

.In FIG. 2, the 'details of the tip 22 and control wire 32 assembly areshown. The control'wire 32is undersize so as to '-loosely fit in thebore 36 with a clearance 40. The face 42 of tip 22 and the end wall 44of the passage 36 is made to be solder wettable, as by means of aninternal rosin flux coating.

In use, power is supplied to theheating element 18, the tip is I broughtup to temperature, and while restraining the lever 26 solder liquifiedand cause it to rise up into the passage 36 as shown in FIG. 4. The freemovement of the solder is aided by the venting of air through theclearance 40 between the wire 32 and the passage 36. The level 50 whichit will rise depends on the particular contact angle between the solderand wall 46, the diameter of the opening, and other known factors as iswell established from the application of general scientific principlesconcerning the phenomenon of surface tension.

The soldering device is then In the charged state, having a quantity ofliquid solder 48 contained in the tip. The joint to be soldered isheated with the tip and coated with a rosin flux. The lever 26 is thenreleased to allow the control wire 32 to advance as shown in FIG. 4' soas to cause the solder to protrude slightly at 50. By touching thisprotrusion to the wires to be soldered, the attraction of. solder forthese wires overcomes the capillary forces to some extent and causes thesolder to flow out onto the joint. However, once the joint has beencoated, the attractive forces are considerably lessened, and capillaryforces reassert themselves on the solder and prevent any additionalflow, thus producing a uniformly perfect joint, without any excesssolder deposits.

As is known from the scientific principles concerning capillarity, thesize of the passage, the angle of the passage, the contact angle, may bevaried so that the capillary forces are developed of the propermagnitude so as to be overcome by the initial attraction for the joint,in order to provide the proper coating for the size of the membersinvolved, as well as to provide a sufficiently quantity of solder. A l/16-inch l.D. passage has proved to be satisfactory for generalelectronic work.

An. alternative arrangement is shown in FIG. 5, where 52 indicatesanother device according to the present invention. In this form, aconcentric passage 54 is formed in the tip, with a solder wettableinsert 56 lining this passage. A vent 58 is provided instead of aclearance gap between the control rod 60 and the passage 54, to allowfree movement of the solder in and out of the tool.

- arm 30 of the lever 26 is a control wire 32, which passes Thisarrangement provides a greater potential solder capacity for moremassive joints.

From the above description, it can be seen that an extremely simpledevice has been provided which is capable of producing uniformly perfectjoints without relying on operator skill by balancing fluid-attractiveforces between the joint and the tool.

In addition, a simplified solder removal. tool has been provided whichdoes not require auxiliary suction assists, but relies on capillaryforces alone.

Iclaim:

I. A soldering tool comprising:

a tip member;

member;

heater means for heating said tip member to the melting point of solder;

means for venting said passage to allow free movement of solder intosaid passage due'to capillary forces; and control means for selectivelycounteracting said capillary forces and causing solder deposited in saidpassage to protrude above the surface of said tip member, wherebycontact of contained solder with members to be connected may befacilitated.

2. The tool of claim 1 wherein said control means includes a controlmember slidably inserted in said passage.

3. The tool of claim 2 wherein said vent means includes a passage formedin said tip having walls which are solder wettable and opening onto thesurface .of said tip

1. A soldering tool comprising: a tip member; a passage formed in saidtip having walls which are solder wettable and opening onto the surfaceof said tip member; heater means for heating said tip member to themelting point of solder; means for venting said passage to allow freemovement of solder into said passage due to capillary forces; andcontrol means for selectively counteracting said capillary forces andcausing solder deposited in said passage to protrude above the surfaceof said tip member, whereby contact of contained solder with members tobe connected may be facilitated.
 2. The tool of claim 1 wherein saidcontrol means includes a control member slidably inserted in saidpassage.
 3. The toOl of claim 2 wherein said vent means includes meansproviding considerable clearance between said control member and saidpassage, and also including another opening to the surface of said tipin communication with said passage.